Cell culture inserts, such as hanging cell culture inserts, are used in conjunction with well plates for the growth and differentiation of various cell types. Cell culture inserts provide access to both apical and basal domains of the cell culture, making it possible to study both sides of a cell monolayer or to study a co-culture of two or more cell types, by creating a biomimicry boundary. However, it can be difficult to control conditions at the apical domain of a cell culture insert. Any manipulation at the apical domain, such as by, for example, providing media to the cell culture, typically requires exposing at least the apical surface of the cell culture to the environment, thereby risking exposure to contaminants. In addition, the direct application of a fluid to the apical surface of a cell culture can result in uneven distribution of the fluid over the cell layer and can cause physical disturbance to the cells themselves.
Specialized cell culture systems have been developed that can provide more precise control of fluid flow to apical and basal surfaces of a cell culture. However, such specialized cell culture systems, which include custom-shaped wells, flow chambers, and cell culture channels, are fully integrated systems that are often incompatible with other cell culture equipment. Such systems can also be harder to operate than conventional hanging cell culture inserts because cell seeding is not as straightforward as seeding with an open insert, which is the common practice in most labs. Additionally, hanging cell culture inserts are more widely available and more frequently used by researchers than such specialized cell culture systems.